Significant Business Transactions and Events - Summary of BFDS and IFDS U.K. Intangible Assets Acquired and Estimated Useful Lives (Details) - USD ($) $ in Millions		1 Months Ended
	Mar. 30, 2017	Mar. 31, 2017
International Financial Data Services U.K. | Acquired software
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful life		6 years
International Financial Data Services U.K. | Client relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired		$ 104.0
Weighted average useful life		10 years
Boston Financial Data Services, Inc. | Acquired software
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful life	5 years
Boston Financial Data Services, Inc. | Client relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 57.2
Weighted average useful life	13 years